The updates and details for each of these are as follows:

Windows 10 Version 1909 | Update: KB5001337 | New Build: 18363.1500Windows 10 Version 1809 | Update: KB5001342 | New Build: 17763.1879Windows 10 Version 1803 | Update: KB5001339 | New Build: 17134.2145Windows 10 Version 1607 | Update: KB5001347 | New Build: 14393.4350Windows 10 Version 1507 | Update: KB5001340 | New Build: 10240.18906

Along with these, April 2021 updates for Windows 10 v2004 & v20H2 have also been released discussions in a separate post. The update includes both security and non-security enhancements and bug fixes. Let us continue to see what these bring to the table.

What’s new in these updates

KB5001337: Windows 10 v1909

Microsoft reminds its users that Windows 10 version 1909 will reach the end of service on May 11th, 2021, which is just less than a month away. Therefore, we suggest that you upgrade to the latest available version.

What’s new in these updates KB5001337: Windows 10 v1909 KB5001342: Windows 10 v1809 KB5001339: Windows 10 v1803 KB5001347: Windows 10 v1607 KB5001340: Windows 10 v1507 Download and install Patch Tuesday updates for April 2021 Download offline installers For Windows 10 Version 1909 For Windows 10 Version 1809 For Windows 10 Version 1803 For Windows 10 Version 1607 For Windows 10 Version 1507 Uninstall the cumulative updates Uninstall updates using Windows Update History tool Uninstall updates using command-line Cleanup after installing Windows Updates

The following security improvements have been made with this release. Please note that these are applicable for Windows 10 versions 2004 and 20H2:

An issue in which a principal in a trusted MIT realm fails to obtain a Kerberos service ticket with an error code “KRB_GENERIC_ERROR from Active Directory Domain Controllers (ADDC) has been fixed. This issue started to occur on the devices that had CVE-2020-17049 protections installed on them.Several security vulnerabilities have been fixed by removing the RemoteFX vGPU feature altogether. Microsoft states that all future updates will not have this feature as it brings along security vulnerabilities, which have been identified by a security researcher. More information can be found on this Remote Code Execution vulnerability CVE-2020-1036.An enhancement has been made to Azure Active Directory (AAD)’s web-based sign-in process to prevent the attack of arbitrary browsing by third-party sign-in sites.Security updates have been made to the following components:Windows App Platform and FrameworksWindows AppsWindows Input and CompositionWindows Office MediaWindows FundamentalsWindows CryptographyWindows AI PlatformWindows KernelWindows VirtualizationInternet ExplorerWindows Media

Known issues: While updating a device from Windows 10 v1809 or later to a later build of the OS, some system and user certificates might be lost. Microsoft states that Windows Update for Business devices, as well as direct connections to Windows Update, won’t be affected. If you are impacted by this, Microsoft suggests that you roll back to the previous version of the operating system using the steps provided in the article down below.

KB5001342: Windows 10 v1809

The Windows 10 version 1809 will also be reaching the end of service on the same day as v1909. Moreover, it introduces the same security fixes as 1909. Known issues: Microsoft is aware that some devices may be experiencing an error message “0x800f0982 – PSFX_E_MATCHING_COMPONENT_NOT_FOUND” with some Asian language packs installed. Microsoft suggests that any users facing this issue should try and reinstall the language packs and then install the April 2019 Cumulative Update. If this does not fix the issue, then they should try and reset their PC.

KB5001339: Windows 10 v1803

This update introduces some different improvements to the OS, along with a few critical security updates. Let’s discuss these in detail:

The following System Registries have been updated to the following default values, and these will no longer be updated automatically:svcKBFWLink = “” (empty string)svcKBNumber = “” (empty string)svcUpdateVersion = 11.0.1000The Volgograd, Russia time zone has been updated from UTC +4 to UTC +3.A new time zone has been added: UTC +2 Juba, Republic of South Sudan.Several security vulnerabilities have been fixed by removing the RemoteFX vGPU feature altogether. Microsoft states that all future updates will not have this feature as it brings along security vulnerabilities, which have been identified by a security researcher. More information can be found on this Remote Code Execution vulnerability CVE-2020-1036.Security updates have been made to the following components:Windows App Platform and FrameworksWindows AppsWindows Input and CompositionWindows Office MediaWindows FundamentalsWindows CryptographyWindows AI PlatformWindows KernelWindows VirtualizationInternet ExplorerWindows MediaThere is now a fix for the problem where users are able to specify up to 255 columns when using the Jet Text Installable Indexed Sequential Access Method (IISAM) format.

Known issues: There are currently no known issues with this update of which Microsoft is aware.

KB5001347: Windows 10 v1607

Here is what has been improved with this update in Windows 10:

The following System Registries have been updated to the following default values, and these will no longer be updated automatically:svcKBFWLink = “” (empty string)svcKBNumber = “” (empty string)svcUpdateVersion = 11.0.1000An issue resulting in the system not working when users sign out or disconnected from a remote session has been addressed.An issue with the heap leak causing the explorer.exe process to consume high amounts of RAM has been fixed.The Volgograd, Russia time zone has been updated from UTC +4 to UTC +3.A new time zone has been added: UTC +2 Juba, Republic of South Sudan.The problem with Windows PowerShell occasionally not working and generating the error “Access Violation” while running multiple PowerShell scripts has been taken care of.The issue of sleep time in the following locations being shorter than expected has been fixed: HKLM\Software\Microsoft\AppV\MAV\Configuration\MaxAttachWaitTimeInMillisecondsAn issue in which a principal in a trusted MIT realm fails to obtain a Kerberos service ticket with an error code “KRB_GENERIC_ERROR from Active Directory Domain Controllers (ADDC) has been fixed. This issue started to occur on the devices that had CVE-2020-17049 protections installed on them.Several security vulnerabilities have been fixed by removing the RemoteFX vGPU feature altogether. Microsoft states that all future updates will not have this feature as it brings along security vulnerabilities, which have been identified by a security researcher. More information can be found on this Remote Code Execution vulnerability CVE-2020-1036.The issue of high memory usage when performing XSLT transforms using MSXLM6 has been fixed.An issue in spaceport.sys that might have caused the error 0x7E has been addressed.An issue with compatibility evaluation of the Windows ecosystem to assist ensure device and application compatibility for Windows updates has been addressed.An issue that prevents users from specifying up to 255 columns when using the Jet Text Installable Indexed Sequential Access Method (IISAM) format has been fixed.Security updates have been made to the following components:Windows App Platform and FrameworksWindows AppsWindows Input and CompositionWindows Office MediaWindows FundamentalsWindows CryptographyWindows AI PlatformWindows KernelWindows VirtualizationInternet ExplorerWindows Media

Known issues: If the “Minimum Password Length” GPO is configured to be greater than 14 characters, the cluster service may fail to start and throw the error “2245 (NERR_PasswordTooShort).” Microsoft suggests that you change the minimum password length to less than or equal to 14 characters while they work on a fix for the issue.

KB5001340: Windows 10 v1507

Here is what installing this update on version 1507 will improve:

The following System Registries have been updated to the following default values, and these will no longer be updated automatically:svcKBFWLink = “” (empty string)svcKBNumber = “” (empty string)svcUpdateVersion = 11.0.1000The Volgograd, Russia time zone has been updated from UTC +4 to UTC +3.A new time zone has been added: UTC +2 Juba, Republic of South Sudan.Several security vulnerabilities have been fixed by removing the RemoteFX vGPU feature altogether. Microsoft states that all future updates will not have this feature as it brings along security vulnerabilities, which have been identified by a security researcher. More information can be found on this Remote Code Execution vulnerability CVE-2020-1036.An issue that prevents users from specifying up to 255 columns when using the Jet Text Installable Indexed Sequential Access Method (IISAM) format has been fixed.Security updates have been made to the following components:Windows App Platform and FrameworksWindows AppsWindows Input and CompositionWindows Office MediaWindows FundamentalsWindows CryptographyWindows AI PlatformWindows KernelWindows VirtualizationInternet ExplorerWindows Media

Known issues: There are currently no known issues with this update of which Microsoft is aware.

Download and install Patch Tuesday updates for April 2021

The size of the updates for each version can vary from a few MBs to up to 2 GB. Surprisingly, the later versions, such as v20H2, take up less space, which climbs up as going to the previous versions. Therefore, we recommend that you give your computer the appropriate time to download and install these updates according to your Windows 10 version. If you are missing any previous updates, installing April 2021 cumulative updates will install all the security fixes included in the previous ones. To install this update using Windows Update, please go to Start Menu –> Settings –> Update & Security –> Windows Update. In the right-hand pane, click on the Check for updates button. You will then be able to see the update and it should start downloading and installing automatically.

Download offline installers

These updates can also be installed on any computer that has the relevant version of Windows 10, without having an internet connection. Download the offline installers below as per your Windows 10 version and platform requirements:

For Windows 10 Version 1909

Download KB5001337 for Windows 10 Version 1909 64-Bit [560.7.8 MB] Download KB5001337 for Windows 10 Version 1909 32-Bit [323.7 MB]

For Windows 10 Version 1809

Download KB5001342 for Windows 10 Version 1809 64-Bit [393.6 MB] Download KB5001342 for Windows 10 Version 1809 32-Bit [174.0 MB]

For Windows 10 Version 1803

Download KB5001339 for Windows 10 Version 1803 64-Bit [1307.3 MB] Download KB5001339 for Windows 10 Version 1803 32-Bit [790.8 MB]

For Windows 10 Version 1607

Download KB5001347 for Windows 10 Version 1607 64-Bit [1667.9 MB] Download KB5001347 for Windows 10 Version 1607 32-Bit [891.2 MB]

For Windows 10 Version 1507

Download KB5001340 for Windows 10 Version 1507 64-Bit [1215.9 MB] Download KB5001340 for Windows 10 Version 1507 32-Bit [714.2 MB] To install the update, simply run the downloaded MSU file and Windows will automatically install the cumulative update. You can check out your current Windows build by launching Run and then typing winver. To download any other updates related to any of the above, please check the Microsoft Catalog.

Uninstall the cumulative updates

Here is a quick guide on how you can uninstall the updates on your computer if you face any issues with them:

Uninstall updates using Windows Update History tool

Uninstall updates using command-line

You can also delete the update by entering several commands in the Command Prompt. Here is how: Restart your computer once the update is uninstalled.

Cleanup after installing Windows Updates

If you want to save space after installing Windows updates, you can run the following commands: